Mycoplasma californicum, a New Species from Cows

Mycoplasmas serologically different from the known Mycoplasma species were found to be important causes of mastitis in California. We describe the cultural, morphological, biological, and serological characteristics of one of these isolates, strain ST-6. In growth inhibition and immunofluorescence tests, we found that strain ST-6 differed from all 75 currently accepted Mycoplasma species and serogroups. Therefore, we regard this strain as a member of a new species for which we propose the name Mycoplasma californicum. Strain ST-6, the type strain, has been deposited in the Collaborating Center for Animal Mycoplasmas, Institute of Medical Microbiology, University of Aarhus, Denmark, under the accession number AMRC-C 1077 and in the American Type Culture Collection under the number ATCC 33461.